To attain the goal of scientific literacy, the nature of science (NOS) is one of the areas that should be addressed. In many countries, the training of scientifically literate generations is a fundamental aim of science education, as a result there is an emphasis on NOS in science curricula and curricular materials. Textbooks prepared to teach curricula should incorporate aspects of NOS for all grades. In Turkey, the secondary science curricula were reformed in 2013. In this document analysis, aspects of NOS were included, the approach adopted for integrating aspects of NOS (i.e., explicit-reflective, implicit, and historical), and content-embeddedness of integration were analyzed in the reform-based and old high school chemistry textbooks published and provided by the National Ministry of Education. The results revealed that from the 9th to the 12th grade, the number of NOS aspects mentioned in the textbooks decreased. The most frequently cited aspects were the tentative nature of scientific knowledge, the empirical basis of science, and the difference between observation and inference. However, models in science, creativity and imagination were NOS aspects that were overlooked. Regarding the approach, contrary to the suggestion of the literature, the implicit approach was employed frequently. Finally, NOS aspects were provided in a content-embedded way in the 9th and 10th grades whereas they were presented mostly in a content-generic way in the 12th grade. Only the 9th grade textbook provided two NOS activities for teaching NOS. Although some changes have been made regarding teaching NOS, some important parts are missing. In light of the results, we suggest that all NOS aspects should be integrated into textbooks in an explicit-reflective way. Additionally, for teaching NOS, explicit-reflective activities should be offered in textbooks.
An Analysis of Analogies in Chemistry Content of Middle School Science Textbooks and High School Chemistry Textbooks Developed under the 2009 Revised National Curriculum
